Average Growth Patterns of Breastfed Babies

Growth charts and breastfed baby growth

I have heard of many breastfed babies (including my own) whose doctor was disturbed at some point because the baby wasn’t gaining weight quickly enough, even though the baby was well within the parameters for weight gain of breastfed babies. The problem is that many doctors are not familiar with the normal weight gain patterns of breastfed babies, and rely too much upon older growth charts that are based upon the growth of artificially fed babies. In 2006, the World Health Organization released revised growth charts that are representative of healthy breastfed babies throughout the world. Until doctors are familiar with them, we need to keep ourselves informed so that doctors don’t undermine our confidence to breastfeed our babies.

Healthy breastfed infants tend to grow more rapidly than their formula-fed peers in the first 2-3 months of life and less rapidly from 3 to 12 months. All growth charts available before 2006 (which are still used by many health care providers in the US) included data from infants who were not exclusively breastfed for the first 6 months (includes formula-fed infants and those starting solids before the recommended 6 months). Because many doctors are not aware of this difference in growth, they see the baby dropping in percentiles on the growth chart and often come to the faulty conclusion that the baby is not growing adequately. At this point they often recommend that the mother (unnecessarily) supplement with formula or solids, and sometimes recommend that they stop breastfeeding altogether. Even if mom realizes that her baby is perfectly healthy and doesn’t follow these unnecessary recommendations, she ends up worrying for no reason (and moms don’t need anything extra to worry about!).

Even if a doctor is informed of the difference in growth patterns, she might not be willing to listen…

“When I told my daughter’s pediatrician that I had read that breastfed babies gain weight slower than indicated by the growth charts, and asked what her thoughts were, she said that she didn’t believe that it was true and continued to question my daughter’s weight. She refused to take a look at the article from Pediatrics [see reference below] that I brought to her office. I was rather surprised at this, since she had breastfed her own children. I ended up changing doctors, and my new doctor had no problem whatsoever with my daughter’s rate of weight gain.”

A note about growth charts

A growth chart isn’t a test, where you are striving to get your baby into the 100th percentile. The growth charts show us the statistical distribution of weight, height , etc. in a particular set of babies (or children or adults). So if a baby is in the 50th percentile for weight on the CDC charts, it means that half of the healthy babies of the same age in the US are heavier and half are lighter; if a baby is in the 10th percentile for height, then 90% of babies of the same age in the US are taller and 10% are shorter. Healthy babies, just like adults, can come in all shapes and sizes – a baby in the 3rd percentile can be just as healthy and normal as a baby in the 97th percentile. What doctors are generally looking for on a growth chart is that baby stay relatively consistent in their growth pattern (see above for why this may not happen with earlier growth charts). Growth charts are only one part of the puzzle, however, and must be evaluated along with other factors, including:

What size are baby’s parents? What were their growth patterns as babies? What about baby’s siblings or other family members? Genetics plays a large part in baby’s size, so don’t ignore it.

Growth Chart Comparisons

Average Growth Patterns of Breastfed Infants
The points plotted on the 2000 CDC Growth Charts represent preliminary WHO data
from the average weight-for-age for a small set of infant boys and girls who were
breastfed for at least 12 months. Note how the growth of the healthy breastfed babies
(plotted in red) appears to falter on the CDC growth charts. I’m in the process of updating
this graphic to show data from the finalized WHO charts.

2000 US CDC Growth Charts:

The US Centers for Disease Control revised their standard growth charts in 2000, based upon more recent data which are “representative of the United States population, reflecting the Nation’s cultural and racial diversity.”

Per the CDC Growth Chart FAQ:
Are these charts appropriate for exclusively breast-fed babies?The 2000 CDC growth charts can be used to assess the growth of exclusively breast-fed infants, however when interpreting the growth pattern one must take into account that mode of infant feeding can influence infant growth. In general, exclusively breast-fed infants tend to gain weight more rapidly in the first 2 to 3 months. From 6 to 12 months breast-fed infants tend to weigh less than formula-fed infants.

The 2000 CDC Growth Chart reference population includes data for both formula-fed and breast-fed infants, proportional to the distribution of breast- and formula-fed infants in the population. During the past two decades, approximately one-half of all infants in the United States received some breast milk and approximately one-third were breast-fed for 3 months or more. A Working Group of the World Health Organization is collecting data at seven international study centers to develop a new set of international growth charts for infants and preschoolers through age 5 years. These charts will be based on the growth of exclusively or predominantly breast-fed children.

1977 Growth Charts:

The 1977 growth charts for babies under 2 years old were based on a study conducted in Ohio from 1929 to 1975. The babies in this study:

were primarily fed formula or a combination of breastmilk and formula

often started solids before 4 months

As a result, the 1977 growth charts are not a reliable indicator of the growth of children who:

are breastfed only

delay solids until around six months, as is now recommended by many health organizations

How well do the 2000 CDC Growth Charts estimate growth of breastfed babies?

de Onis and Onyango (2003) used weight and length measurements from a sample of 226 healthy breastfed infants to evaluate the new 2000 CDC Growth Charts and the National Center for Health Statistics/World Health Organization (NCHS/WHO) growth reference. They found that there were “notable differences in the growth trajectory of breastfed infants” and concluded that “A reference based on healthy breastfed infants is required if the growth patterns of infants following international feeding recommendations are to be correctly assessed.” Click to see a chart illustrating this difference.

WHO growth charts

Iota Charts is a free web-based service for tracking your baby’s growth on the WHO growth charts.

Standard growth charts

CDC Clinical Growth Charts. Weight for age and length for age charts are much less important than the weight for length (growth velocity). If your baby is staying relatively consistent on the weight per length chart, then he/she is likely to be growing perfectly fine.

Growth Charts from KidsGrowth.com. Current CDC Growth charts, plus charts for children born prematurely, and children with Down Syndrome, Turner Syndrome and Cerebral Palsy.

Child Growth Charts of height weight and body mass index from halls.md. The growth charts available on this web page are derived from NHANES III data (a comprehensive survey of the American population during years 1988-1994). This data was re-analyzed and re-plotted for the halls.md growth charts.

Conclusion: As was the case when compared with the NCHS/WHO reference, there are notable differences in the growth trajectory of breastfed infants examined against the CDC reference. A reference based on healthy breastfed infants is required if the growth patterns of infants following international feeding recommendations are to be correctly assessed.

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